Authors: Tim Roberts, Extension Specialist and Assistant Professor, Virginia Tech; Ruby Cox, Extension Specialist and Associate Professor, HNFE, Virginia Tech;
Publication Number 348-597, Posted February 1999
Look at this link for Why Dry?
Food
Preparation
Drying
Pasteurizing and
Conditioning of Dried Foods
Storing the
Food
Reconstituting
Dried Foods
References
Heat - high enough to force out moisture but not hot enough to cook
the food
Dry air - to absorb the released moisture
Air movement - to carry the moisture away
Natural drying, outdoors, requires warm days of 90 degrees F (32 degrees C)
or more, low humidity, and control of insects. Oven drying or using a food
dehydrator are alternatives for small quantities of food. The energy cost of
operating an oven is high, however, compared to the cost of operating an
electric food dehydrator.
Vegetables may be steam or water blanched as follows.
Steps for steam blanching
Steps for water blanching
Dipping is an alternative to blanching used to prevent fruits
such as apples, bananas, peaches, and pears from turning brown. Lemon juice,
ascorbic acid, or commercial products containing ascorbic or citric acid may be
used for dipping. For instance, dipping sliced fruit pieces in 1 teaspoon of
ascorbic acid crystals per cup of water or directly in lemon juice for three to
five minutes will prevent browning.
* Dried vegetables should be brittle or crisp.
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NOTE: Sun drying is not recommended in cloudy or humid weather. The
temperature should reach 90 degrees F by noon and the humidity should be less
than 60 percent.
Oven Drying
* Fruits may be dipped in ascorbic acid or citric acid in place of blanching.
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Dried fruits must be conditioned prior to storage. Conditioning is the
process of evenly distributing moisture present in the dried fruit to prevent
mold growth. Condition dried fruit by placing in a plastic or glass container,
sealing and storing for 7 to 10 days. The dried fruit in the containers should
be shaken daily to distribute moisture. If condensation occurs, place the fruit
in the oven or dehydrator for more drying and repeat the conditioning process.
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Dried foods should be used within 3 to 6 months as they will lose their
flavor and color to some extent during storage.
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Contents
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Contents
Food Preservation in Alabama, Alabama Cooperative Extension Service, Auburn
University, 1995.
For additional information on drying fruits and vegetables, contact the local Virginia Cooperative Extension
office in your area.
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Contents
Food Preparation
You need 3 things for successful home food drying:
Fruit
Vegetable
Apples
Snap Beans
Apricots
Beets
Bananas
Carrots
Cherries
Sweet Corn
Citrus Peel
Garlic
Coconuts
Horseradish
Figs
Mushrooms
Grapes
Okra
Nectarines
Onions
Peaches
Parsley
Pears
Peas
Pineapples
Hot and Sweet Peppers
Plums
Irish Potatoes
Rhubarb
Pumpkin
Tomatoes
Vegetable
Blanching Time
Drying Time*
Method
Minutes
Method
Hours
Broccoli
Steam
3 -- 3-1/2
Sun
8 -- 10
Water
2
Oven
3 -- 4-1/2
Snap Beans
Steam
2 -- 2-1/2
Sun
8
Water
2
Oven
3 -- 6
Beets
Cook before drying
Sun
8 -- 10
Oven
3-1/2 -- 5
Carrots
Steam
3 -- 3-1/2
Sun
8
Water
3-1/2
Oven
3-1/2 -- 5
Onions
Not necessary
Sun
8 -- 11
Oven
3 -- 6
Peppers
Not necessary
Sun
6 -- 8
Oven
2-1/2 -- 5
Summer Squash
Steam
2-1/2 -- 3
Sun
6--8
Water
1-1/2
Oven
4 -- 6
Winter Squash
Steam
21/2 - 3
Sun
6 - 8
Water
1
Oven
4 -- 5
Tomatoes
Steam
3
Sun
8 -- 10 Drying
Natural Sun Drying
Fruit
Blanching Time*
Drying Time**
Method
Minutes
Method***
Hours
Apple
Steam
5
Sun
36 -- 48
Oven
6 -- 12
Apricots
Steam
3 -- 4
Sun
24 -- 36
Water
4 -- 5
Oven
24 -- 36+
Figs
Not necessary
Sun
48 -- 60
Oven
12 -- 20
Grapes: seedless
Not necessary
Sun
36 -- 60
Oven
12 -- 20
Peaches
Steam
8
Sun
36 -- 60
Water
8
Oven
36 -- 48+
Pears
Steam
6
Sun
60
Water
8
Oven
24 -- 36+
** Test for dryness by cutting the fruit. There should be no moist areas in
the center of the fruit.
*** A food dehydrator could be used in place of a
range oven due to the extended drying times for most fruits.
+ Drying times
for whole fruits. Drying time may be shortened by cutting fruit into slices.
Fresh Fruits
Dehydrated
apples, 20 lbs.
2 lbs.
peaches, 20 lbs.
1-1/2 - 2-1/2 lbs.
pears, 20 lbs
2-1/4 lbs.
prunes/plums, 20 lbs.
2-1/4 lbs.
Fresh Vegetables
Dehydrated
snap beans, 20 lbs.
1-3/4 lbs.
beets, 20 lbs
2 lbs.
carrots, 20 lbs.
1-3/4 lbs.
onions, 20 lbs.
2-1/2 lbs.
squash (summer), 20 lbs.
1-1/2 - 2 lbs.
tomatoes, 20 lbs.
3/4 lbs. Pasteurizing and Conditioning of Dried Foods
All sun-dried fruits and
vegetables must be pasteurized to destroy insects. Place dried food evenly in
shallow trays no more than 1 inch in depth. Vegetables should be heated at 150
degrees F for 30 minutes or 160 degrees F for 10 minutes. Fruits should be
heated at 160 degrees F for 15 minutes.
Storing the Food
Cool dried food should be placed in a closed container
that has been washed and dried before storing. Home canning jars are good
containers for storing dried foods. Store in a cool, dry, dark place.
Reconstituting Dried Foods
Dried fruits and vegetables may be
reconstituted (restoring moisture) by soaking the food in water. Time for
reconstituting will depend on the size and shape of the food and the food
itself. Generally most dried fruits can be reconstituted within 8 hours, whereas
most dried vegetables take 2 hours to be reconstituted. To prevent growth of
microorganisms, dried fruits and vegetables should be reconstituted in the
refrigerator. One cup of dried fruit will yield approximately 11/2 cups of
reconstituted fruit. One cup of dried vegetable will yield approximately 2 cups
of reconstituted vegetable. Reconstituted fruits and vegetables should be cooked
in the water in which they were soaking.
References
Complete Guide To Home Canning, Extension Service, USDA,
1994.